It is known that vehicular indicators are typically located proximate an instrument panel area. As seen in FIGS. 6 and 7, such indicators may include, for example, a gauge assembly, which is seen generally at reference numeral 100. Such conventional gauge assemblies 100 are typically lit using a relatively large number of light sources, one of which is referenced generally at reference numeral 102. Light, L, from the light sources 102 pass through a graphic applique 104 to create an effect or design theme. Appliques 104 typically include layers of multiple ink passes (not shown) that are screened on a polycarbonate substrate, which define the graphics. The ink passes diffuse the light intensity to create a balanced display for viewing by a vehicle operator. As illustrated, the light sources 102 are arranged directly behind the applique 104 so that the resulting light, L, cones-out in a cone-like shape 106 to illuminate the graphics.
Placement of the light sources 102 is important in creating a luminously-balanced display. If the display is not luminously balanced, “hot spots” or shadows may occur due to the location of other interior components (i.e., electrical or structural components) of the design. Specific examples of light sources 102 most often used include incandescent bulbs, light emitting diodes (LEDs), or an electro-luminescent film. Traditionally, incandescent bulbs are used because incandescent bulbs produce a high intensity, very repeatable, wide-cone “white light” (i.e., light which covers a large portion of the visible spectrum). However, when LEDs are implemented, the gauge assembly 100 may require a large quantity of LEDs to create luminously balanced intensities because LEDs typically provide a narrow-cone propagation of light, L, at a higher intensity in comparison to the light output of incandescent bulbs. Such implementations may comparatively require approximately six incandescent lamps or approximately twenty LEDs.
In general, the light, L, from any selected light source 102 may be of a higher than required intensity, and the excess light, L, is typically blocked by using diffusion and compensation ink passes on the applique 104. Thus, extra care must be taken when designing conventional luminously-balanced gauges 100, which are limited to a white daytime appearance and a different, non-white (i.e. green or amber), nighttime appearance.